POS1138 PERSISTENCY OF DEPRESSIVE SYMPTOMS AND PHYSICAL PERFORMANCE IN KNEE OSTEOARTHRITIS
Authors: R. Mehta, M. Shardell, A. Ryan, Y. Dong, B. Beamer, J. Gallo, E. Stuart, M. Schuler, M. Hochberg, A. Rathbun
Journal: Annals of the Rheumatic Diseases (2022)

Background Knee osteoarthritis (OA) is the most prevalent arthritic disorder, characterized by joint paint, which is exacerbated by chronic depressive episodes. Depression in knee OA is also associated with declines in physical activity level and greater disability; however, the impact of persistent depressive symptoms on physical performance remains unclear. Objectives To determine how the persistence of depressive symptoms affects functional capacity in knee OA. Methods Participants (n=2,212) were from the Osteoarthritis Initiative cohort and included individuals with radiographic disease (Kellgren-Lawrence grade ≥ 2) and complete data on study measures at baseline. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D; range 0-60) at baseline and the first three follow-up visits. Physical Performance was measured using 20-meter gait speed (meters per second) during follow-up at the first four annual visits. Persistency of depressive symptoms was operationalized as a cumulative exposure using average severity over time. Gait speed was standardized so that outcome estimates could be interpreted in standard deviations. Time-invariant confounders measured at study enrollment included demographic, socioeconomic, and lifestyle factors. Time-varying confounders assessed concurrent to CES-D scores were body mass index, analgesic medications, pain, and other knee OA signs and symptoms. Marginal structural models accounting for time-dependent confounding and selective attrition were the primary method of analysis. The outcome model included all potential statistical interactions between depressive symptoms and follow-up time indicators. Post-estimation linear combinations estimated time-specific effects of time-averaged CES-D scores on standardized gait speed and differences in physical performance between participants with (i.e., CES-D=16) and without (i.e., CES-D=0) depressive symptoms satisfying screening criteria for major depression. Results The interaction between depressive symptoms and time was statistically significant (P=&lt;0.001). Time-specific associations indicated that the largest negative impact of depressive symptoms on physical performance was from baseline through year one (β = -0.0077; 95% CI: -0.0125, 0.0030). However, the effect of persistent depressive symptoms decreased over time and reversed in magnitude and directionality, evidenced by the time-specific associations between time-averaged CES-D scores from baseline through year one and year two and gait speed at year two (β = -0.0033; 95% CI: -0.0084, 0.0019) and year three (β = 0.0014; 95% CI: -0.0046, 0.0074), respectively. Consequently, the strongest negative affect of depressive symptoms on gait speed (β = -0.1232; 95% CI: -0.1998, -0.0473) between participants with and without depressive symptoms satisfying screening criteria for major depression was when depressive symptoms were first measured closest to the initial gait speed assessment. Conclusion In the contrast to the dose-dependent relationship between chronic depressive episodes and pain in knee OA, study findings imply that the negative effect of depressive symptoms on physical performance decreases over time with increasing depression persistency. These results may reflect diminishing marginal effects, where the largest impact on physical performance in knee OA is during the first depressive episode closest to initial gait speed assessment, especially when averaged against improvement in symptoms over the same duration. Acknowledgements The OAI is a public-private partnership comprised of five contracts (N01-AR-2-2258; N01-AR-2-2259; N01-AR-2-2260; N01-AR-2-2261; N01-AR-2-2262) funded by the National Institutes of Health, a branch of the Department of Health and Human Services, and conducted by the OAI Study Investigators. Private funding partners include Merck Research Laboratories; Novartis Pharmaceuticals Corporation, GlaxoSmithKline; and Pfizer, Inc. Private sector funding for the OAI is managed by the Foundation for the National Institutes of Health. This manuscript was prepared using an OAI public use data set and does not necessarily reflect the opinions or views of the OAI investigators, the NIH, or the private funding partners. Disclosure of Interests Rhea Mehta: None declared, Michelle Shardell: None declared, Alice Ryan: None declared, Yu Dong: None declared, Brock Beamer: None declared, Joseph Gallo: None declared, Elizabeth Stuart: None declared, Megan Schuler: None declared, Marc Hochberg Shareholder of: Dr. Marc C. Hochberg is the President of Rheumcon Corporation., Consultant of: Dr. Marc C. Hochberg receives consulting fees from Bioiberica SA, Bristol-Myers Squibb, Eli Lilly, EMD Serono, Galapagos, IBSA Biotechniq SA, Novartis Pharma AG, Pfizer, Plexxikon, Samumed LLC, Theralogix LLC, and TissueGene Inc., Alan Rathbun: None declared